Underwater electrical connector

ABSTRACT

A disconnectable electrical connector assembly capable of being connected and disconnected under water, at any depth, during the presence of a voltage potential applied to one or more contacts of the connector. The connector assembly includes two mateable halves wherein the contacts of one half or both halves are immersed in an oil bath. The mateable halves are designed so that, after mating, the contacts of each respective half are immersed in a common oil bath. Both halves of the connector assembly are connected to resiliently deformable plastic cable conduits that contain a nonconducting fluid which when submerged in water, to any depth, is pressurized to ambient pressure thereby eliminating any differential pressures across the fluidtight seals in the connector assembly.

(451 Oct. 29, 1974 UNDERWATER ELECTRICAL CONNECTOR [75] Inventors: Judson C. Cole, Sidney; James R.

Hall, Bainbridge, both of NY.

[73] Assignee: The Bendix Corporation, Bendix Center, Southfield, Mich.

[22] Filed: Dec. 26, 1972 [211 App]. No: 318,342

[52] US. Cl. .l 339/42, 339/94 M, 339/117 R [5 1] Int. Cl H0lr 33/36, H0lr 13/52 [58] Field of Search 339/l6, 15, 42, 94,60,

[56] References Cited UNITED STATES PATENTS 327L725 9/l966 Bloch 339/42 3,49l,326 l/l970 Pfister et al 339/42 3,508 l88 4/l970 Buck t 339/42 3,524,l60 8/1970 Robinson r 339/42 X 162L447 ll/l97l Taylor et a] 339/94 M Primary Examiner-Roy D. Frazier Assistant Examiner-Terrell P. Lewis Attorney, Agent, or Firm-Raymond J. Eifler [57] ABSTRACT A disconnectable electrical connector assembly capable of being connected and disconnected under water, at any depth, during the presence of a voltage potential applied to one or more contacts of the connector. The connector assembly includes two mateable halves wherein the contacts of one half or both halves are immersed in an oil bath. The mateable halves are designed so that, after mating, the contacts of each respective half are immersed in a common oil bath. Both halves of the connector assembly are connected to resiliently deformable plastic cable conduits that contain a nonconducting fluid which when submerged in water, to any depth. is pressurized to ambient pressure thereby eliminating any differential pressures across the fluid-tight seals in the connector assembly.

6 Claims, 2 Drawing Figures 1 UNDERWATER ELECTRICAL CONNECTOR BACKGROUND OF THE INVENTION This invention relates to sealed. water-tight electrical connectors and in particular to connectors and connector assemblies which may be coupled or uncoupled under water at any depth without exposing electrical contacts to the water and thereby eliminating the need for disconnecting the electrical power from the attached cables. This invention is more particularly related to a disconnectable underwater electrical connector and cable assembly that is capable of withstanding pressures up to at least 2.500 PSlG without failure.

With the advent of rapid growth in oceonographic exploration. it has become necessary to provide underwater electrical equipment which is both reliable and relatively inexpensive. While underwater electrical connectors have previously been developed which allow mating or unmating while submerged. most successful underwater connectors to date require that the mating occur above the water surface prior to an exposure to an underwtaer environment. However, with the use of electronic equipment at greater and greater depth. it has become a necessary expedient that mating and unmating occur below the water surface and at depths that would subject the connector to high hydro static pressures.

Disconnectable underwater electrical connector assemblies generally consist of two connector halves that are mateable. each of which including some type of sealing means to prevent sea water from entering the electrical connector when mated and/or separated. Obviously, the limitation on the effectiveness of the connectors assembled or disassembled is a function of the effectiveness of the sealing means, i.e. as the sealing means is subjected to greater and greater differential pressures when it is lowered into water. it is more prone to failure and, in fact. does fail when a differential pres sure exceeds the sealing capacity of the sealing means, usually. underwater connector devices use interference-type fittings and ring type sealing members to prevent the entrance of liquid into the electrified portion of the mated connectors.

Examples ofdisengageable electrical connectors hav ing protected contacts and/or sealing means to protect the contacts from exposure to moisture and water may be found in US. Pat. No. 3.49l,326 entitled Disengageable Electrical Connector with Contact Protecting Means issued Jan. 20. I972. to F. Pfister et al.; and U.S. Pat. No. 3.508,l88 entitled Underwater Electrical Quick Disconnect issued Apr. 21. I970 to J. R. Buck. In both the aformentioned patents. as the plug and receptacle. either mated or unmated. are lowered into the sea and subjected to greater and greater pressures. a differential pressure builds up across the sealing means until eventually the seal fails and water en ters the connectors. thereby causing an electrical failure. A further disadvantage of a connector built in accordance with the teachings of the Pfister patent is that the surfaces that engage the 0" ring to form the fluidtight seals are exposed and therefore subject to damage from external sources. Any scratches and/or dents in the sealing surface results in a bad seal with the 0 ring which will further result in leakage and failure of the connector.

SUMMARY OF THE INVENTION This invention provides an underwater electrical connector and cable assembly capable of being mated under water, at any depth, without failure because of the elimination of differential pressures across the sealing means of the connector.

The invention is an underwater electrical connector/- cable assembly characterized by a resiliently deformable cable conduit 300 containing an electrically nonconducting fluid that fills the voids within the conduit and the electrical connector so that when the assembly is submerged. to any dpeth, no differential pressures of any significance arise between the outside and the inside of the connector and cable assembly.

ln one embodiment of the invention, the underwater electrical connector and cable assembly comprises: a housing having a forward mating end 102 a rear conduit receiving end 104 and a central axis from said forward end to the rear end; a plurality of electrical contacts having a mating end 112 and a conduc' tor receiving end 114', means for mounting 123 the electrical contacts 110 in spaced relationship around said housing central axis so that the mating ends 112 of said contacts 110 are at the mating end 102 of said housing 100'. means for establishing a fluid-tight seal 170, 121, 123 at the mating end of said housing 100, said sealing means including a forwardly biased 122 portion 121 that covers the mating end 112 of said contacts 110 and maintains the fluid-tight seal when the contacts 110 are covered and is rearwardly movable upon mating with a receptacle 200 to expose the contacts 110 and engage corresponding receptacle contacts 210. said covering means 121 defining with said housing 100 a cavity within which at least a portion of the mating ends 112 of the electrical contacts 110 are disposed. the cavity 120 communicating with the rear conductor receiving cavity poriton of the housing 100; a water-tight resiliently deformable conduit 300 connected to the conduit receiving end 104 of the housing 100, the conduit 300 including therein a plurality of electrical conductors 400 connected to the respective conductor receiving ends 114 of said contacts 110; and electrically nonconducting fluid filling the remaining space in said conduit 300 and said housing cavities 120. 140, whereby the mating ends 112 of said electrical contacts 110 are substantially surrounded by said nonconductive fluid, said forward mating end 102 of said housing 100 adapted to receive within said housing 100, in fluid tight relationship. a portion 202, 223 a receptacle 200 having receptacle contacts 212 so that the housing 100 and receptacle 200 contacts I12, 212 are in contact with the nonconducting fluid in said housing cavity 120 upon mating within said housing 100.

Accordingly. it is an object of this invention to provide an electrical connector and cable assembly for use under water that is not subject to high differential pressures between the internal portions of the connector and external sea water when the connector and cable are submerged to great depths.

lt is another object of this invention to provide a disconnectable electrical connector assembly that is mateable under water.

It is still another object of this invention to provide an underwter electrical connector that is mateable under water while an electrical potential is present at the electrical contacts of at least one half of the electrical connector assembly.

It is a further object of this invention to provide an electrical connector/cable assembly for high voltage applications.

It is still a further object of this invention to provide an electrical connector assembly that contains oil or a similar dielectric medium between the electrical contacts therein so that the connector is useful at much higher voltages than ordinary connectors.

The above and other objects and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings and claims which form a part of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an axial partial cross-sectional view of an electrical connector and cable assembly embodying the invention. the respective connector parts being shown in the unmated position.

FIG. 2 is a view similar to FIG. I but showing two connector halves in the mated position.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings. FIG. 1 illustrates a connector and cable assembly that includes a plug 100 and receptacle 200 and conduits 300 connected in fluid-tight relationship to the end of a respective plug and receptacle. The plug portion of the assembly includes a housing 100 having a forward mating end 102 and a rear conduit receiving end I04. A resiliently deformable conduit 300, e.g. made from an elastomer is attached to the conduit receiving end I04 to form a fluid-tight seal. Within the housing 100, a plurality of electrical contacts 110 having a forward mating end I12 and a rear wire receiving end 114 are mounted in a circumferential manner and in spaced relationship around the central axis of the housing I23. In this embodiment the contacts are mounted within a generally tubular housing 123 that has telescoped therein a second generally cylindrical housing 121 that is forwardly biased by a spring 122 to a first contact covering position. The generally cylindrical inner housing I2I in its forward biased and contact covering position is in pressure contact with 0" rings I70 to form a fluid-tight seal between the outer tubular housing I23 & inner cylindrical housing I21, thereby protecting the contacts 0 and their forward mating ends I12 from coming into contact with external fluid. All voids I20, I40 within the housing I00 and resiliently deformable conduit 300 are filled with a nonconducting fluid. such as mineral oil. The fluid in the housing I00 and cable 300 communicating with the mating ends 112 and ocnductor receiving ends 114 of the contacts and with the wires 400 in the conduit 300 so that. at all times, the mating ends N2 of the contacts are immersed in the nonconducting fluid. Electrical contacts 0 are circumferentially arranged so as to be in contact with the outside of the tubular housing I21 which is telescoped within housing I23. The cylindrical housing IZI is rearwardly movable within tubular housing 123. The remaining structure of the plug assembly being similar to and serving the same functions as any other electrical connector plug assembly.

The receptacle includes a housing 200 that has a forward mating end 202 and a rear conduit receiving end 204. Mounted within the receptacle housing 200 are a plurality of electrical contacts 210 circumferentially arranged around the central axis of cylindrical housing 221 in the same spaced relationship as the corresponding plug contacts 110. In the receptacle assembly, the inner cylindrical housing 221 which is telescoped within the outer tubular housing 223 forms a fluid-tight seal at the front of the receptacle with tubular housing 223 by means of "0 rings 270. In the receptacle half the outer tubular housing 223 is forwardly biased by a spring 222 which maintains the 0" ring 270 in pressure contact with the wall of inner housing 221, thereby assuring a fluid-tight seal and protecting the electrical contacts 210 from exposure to sea water when the receptacle is immersed therein. The tubular housing 223 is rearwardly movable upon the application of a rearward force supplied to the front end of the tubular housing 223. The 0" ring 270 maintains a fluid-tight seal along the outside of the cylindrical inner housing 221. In this embodiment. the cylindrical housing 22] generally comprises a smooth rod of insulating material with the matching ends 2I2 of the contacts flush with the surface of the housing 221. All the voids within the conduit 300 and the connector housing 200 are filled with a nonconducting fluid and the 0" rings 270 maintain a fluid-tight seal between the fluid within the connector assembly and conduit and the water in which the assembly is immersed.

FIG. 2 illustrates the connector assembly in its mated position. In the mated position, the receptacle tubular housing 223 is forced rearwardly of the receptacle housing 200 and the cylindrical housing 121 of the plug assembly I00 is forced rearwardly with respect to housing so as to allow the receptacle contacts 210 to mate with the plug contacts at their respective mating ends 2l2, I I2. It should be noted at this point that the contacts are mated within the plug housing 100 and in the nonconducting fluid common to the plug housing 100 and plug conduit 300. 0" rings 270 and prevent the nonconducting fluid in the receptacle from entering the plug and conversely the nonconducting fluid in the housing 100 from entering the receptacle housing 200. A preferable nonconducting fluid would be oil, Freon, or any other suitable electrically nonconductive fluid.

OPERATION Referring now to the drawings, the connector assembly is mateable under water as follows: a key way (not shown) aligns the receptacle contacts 210 with the plug contacts 110 when the receptacle is inserted into the forward end 102 ofthe plug housing I00. As the receptacle is pushed into the plug housing. the tubular housing 223 abuts against the tubular plug housing 123 forcing the receptacle housing 223 rearwardly. Simultaneously. the receptacle cylindrical housing 221 abuts against the cylindrical plug housing I21 forcing the plug cylindrical housing I21 rearwardly with respect to the housing 100. As the forward portion of the receptacle cylindrical housing 221 moves into the plug housing 100 the receptacle contacts 212 are wiped by the 0" rings 170 which are in pressure contact with the cylindrical housing 221 to form a fluid-tight seal therewith. As the plug cylindrical housing 12! moves rearwardly. the receptacle contact mating end 212 comes into Contact with the forward mating end II2 of the plug contact 110. Lock ring 106 maintains both halves of the connector assembly in their mated position by threadably engaging the forward portion 202 of the receptacle housing.

To disconnect the connector assembly, the locking TEST NO. 3

The connector/cable assembly was immersed in a salt water solution and repeatedly mated and unmated under water. The following data shows the initial resis mil 106 is disengaged and the hohhectol' halves are 5 tance measured (gigaohms) between adjacent contacts pulled apart. if the connector halves were under water before immersing th bl i water compared to at this time, no water would enter the contact containth resistancameasured after each cycle (unmatinging portions of the respective connector halves. This is mating):

ADM lNlTlAL In 3d 5th "in? 6th 5th CENT RESISTANCE CONTACTS GIGAOHMS CYCLE CYCLE CYCLE YCLE CYCLE CYCLE A43 90 9.2 I 3 0.0 6,! 5.1 C-D 5.8 as 6.7 $5 5.5 as 4.8 E-F 7.8 8.6 as s 2 5.2 5,9 4.7

because the action of the resiliently deformable con- The foregoing tests show that the connector and duits which, when subjected to pressure, increase the cable assembly was capable of withstanding pressures pressure of the nonconducting fluid within the connecup to and including 2,500 PSIG with little or no adverse tor against the O ring seals I70, 270 so that the preseffects and that the unit functioned satisfactorily, both sure of the nonconducting fluid within the conduit 300 mechanically and electrically when mated repeatedly and the housings 100,200 equals the pressure of the sea under water. water external .to the housings 100, 200. Since there is While a p f rr d d nt f the invention has little or no differential pressure acrgss the 0" ring been disclosed, it Will be apparent to lhOSC skilled in the seals 170, 270, seawater will not enter the plug or ref Changes may he hlade to h lhvemic" as Set ceptacle housing. Obviously, if the conduit 300 was not forth m h pp e claims. In some cases, d f mable there w ld b no way f equalizing th tain features of the nvention may be used to advantage internal nonconducting fluid pressure to sea water WilhQui Corresponding use 9 other featurfis- For m pressure. Since the conduit 300 is resiliently compress- P some PP Q It m y be desirable to i ible, as the cable and connector assembly go to greater have a "Oncunductmg flulfll Within y the P or and greawr depths and the Sea water pressure against ceptacle half of the electrical connector and cableasthe conduit 300 increases, the conduit 300 compresses, ythis regard; the P Portion of the electrical thereby increasing the pressure of the nonconducting cohhec'lor 9 \5 prefel'hed to h the hohcoh' fluid so as to prevent sea water from entering into the duchhg i F Q Y l lmehded that connector assembiy through the 0" ring Seals the illustrative and descrlptlve materials herein be used To establish the effectiveness of this new connector, :9 -fir tfi 'th of the and not imit e scope ereo followmg tests were performed Having thus described the invention, what is claimed 15: TEST 40 1. An underwater electrical connector and cable as- Pairs of adjacent electrical contacts and their atmbl c mprising; tached wires were connected together in series and a 5 a plug housing having a forward mating end, a rear amp current was passed through the resultant circuit. conduit receiving end and a central axis from said The following voltage drops (millivolts) were measured forward end to said rear end; across the contacts when the assembly was immersed a first plurality of electrical contacts having mating in water and pressurized to 2,500 P810 and then re ends and conductor receiving ends; moved: means for mounting said first plurality of electrical contacts in said plug housing and in spaced relationship around said plug housing central axis so that DROP g figg To the mating end of said contacts are at the mating lNlTlAL HYDROSTATIC PRESSURE or I of Sam housmg? CIRCUIT VOLTAGE 250i] PSIG FOR ONE HOUR sealing means for establishing a fluid-tight seal at the DROP mating end of said plug housing, said sealing means including a forwardly biased portion that covers (0mm 567 My 575 MV said contacts and maintains a fluid-tight seal when CunlaCIS C-o 5w MV 5x5 MV satd contacts are covered and IS rearwardly mov- Ctmwrl-s 567 MW able to expose said contacts, said sealing means defining with said plug housing a cavity within which at least a portion of the mating ends of said contacts mounted in said plug are disposed, said cavity communicating with the rear conduit receiv- TEST 2 ing end of said plug housing; An ac voltage of 4,800 volts r.m.s. was applied to two a first water-tight resiliently deformable, conduit adjacent connector contacts, electrically isolated from 66 connected at one end to the conduit receiving end each other, while the connector was subjected to a hydrostatic pressure of 2500 PSlG. No flashover Occurred between the contacts and the interfaces between the plug and receptacle when unmated were free of water.

of said plug housing, said conduit including therein a plurality of electrical conductors, each having one end connected to a respective conductor receiving end of said contact mounted in said plug;

an electrically nonconducting fluid filling the remaining space in said conduit and said plug cavity whereby the mating ends of said contacts mounted in said plug are substantially surrounded by said nonconducting fluid, said forward mating end of said plug adapted to receive a receptacle having contacts within said plug housing so that said contacts mounted in said plug are in contact with the nonconducting fluid in said plug cavity upon mating of said plug with a receptacle;

a receptacle housing having a forward mating end, a rear conduit receiving end and a central axis from said forward end to said rear end;

a second plurality of electrical contacts having mating ends and conductor receiving ends;

means for mounting said second plurality electrical contacts in said receptacle housing and in spaced relationship around said receptacle housing central axis so that the mating end of said contacts are at the mating end of said receptacle housing and said contacts mounted in said receptacle engage said contacts mounted in said plug upon mating of said plug and receptacle;

sealing means for establishing a fluid-tight seal at the mating end of said receptacle housing, said sealing means including a forwardly biased portion that covers said contacts mounted in said receptacle and maintains a fluid-tight seal when said contacts mounted in said receptacle are covered and is rearwardly movable to expose said contacts mounted in said receptacle upon mating, said receptacle covering means defining with said receptacle housing a cavity within which at least a portion of the mating.

ends of said contacts mounted in said receptacle are disposed, said cavity communicating with the rear conduit receiving portion of said receptacle housing;

the other end of said first water-tight, resiliently deformable conduit connected to the conduit receiving end of said receptacle housing, said nonconducting fluid filling said receptacle cavity also, whereby at least a portion of the mating ends of said contacts mounted in said receptacle are surrounded by said nonconducting fluid and whereby said nonconducting fluid in said conduit communicates with said plug cavity and said receptacle housing.

2. An underwater disengageable electrical connector for interconnecting a plurality of electrical conductors, the electrical connector comprising:

a receptacle element;

a plug element disengageably insertable into said receptacle element, said plug element having a housing assembly carrying circumferentially spaced electrical contacts, a mating end, a conduit receiving end, and sealing means for establishing a fluidtight seal at the mating end of said housing assembly, said sealing means including movable means for covering said contacts on said plug element and means for biasing said contact covering means in a contact covering position, said covering means biased to a contact covering position upon disengagement of said elements and a contact exposing position upon mating of the plug and receptacle;

said receptacle element having a housing assembly carrying circumferentially spaced electrical contacts each engageable with a respective contact in said plug, a mating end, a conduit receiving end, and sealing means for establishing a fluid-tight seal at the mating end of said receptacle housing assembly, said sealing means including movable means for covering said contacts in said receptacle and means for biasing said receptacle contact covering means in a contact covering position, said receptacle contact covering means biased to a receptacle contact covering position upon disengagement of said elements and a contact exposing position upon mating of said plug and receptacle;

said contacts in said plug and receptacle having a an electrically nonconducting fluid filling the remaining space in said conduit and said cavities in said housing assemblies.

3. A disengageable electrical connector, as claimed in claim 2, in which said plug element includes a tubular housing having an open outer end and an inner surface, said inner surface mounting said plug contacts; said plug contact covering means comprising a hollow member telescoped inside said tubular housing; said plug biasing means comprising a first spring biasing said hollow member to a contact covering position; and at least one sealing ring mounted in said housing inner surface adjacent said housing open outer end and engageable with the external surface of said hollow member to form a seal therewith.

4. A disengageable electrical connector as claimed in claim 2 in which said receptacle contact carrying part has an outer surface mounting said receptacle contacts; said receptacle contact covering means comprising a member telescoped over the receptacle contact carrying part and displaceable axially relative to said receptacle part; an annular seal mounted between said receptacle part and said member to form a seal therebetween; and said receptacle biasing means comprising a second spring biasing said member to a contact covering position.

5. A disengageable electrical connector as claimed in claim 3 in which said receptacle contact carrying part has an outer surface mounting said receptacle contacts; said receptacle contact covering means comprising a member telescoped over the receptacle contact carrying part and displaceable axially relative to said receptacle part; an annular seal mounted between said receptacle part and said member to form a seal therebetween; and said receptacle biasing means comprising a second spring biasing said member to a contact covering Position.

6. An underwater electrical connector and cable assembly comprising:

housing having a forward mating end, a rear conduit receiving end, a rear conductor receiving portion, and a central axis from said forward end to said rear end;

a plurality of electrical contacts having a mating end and a conductor receiving end;

means for mounting said electrical contacts in spaced relationship around said housing central axis so that the mating end of said contacts are at the mating end of said housing;

sealing means for establishing a fluid-tight seal at the mating end of said housing, said sealing means including a forwardly biased portion that covers said contacts and maintains a fluid-tight seal when said contacts are covered but is rearwardly movable to expose said contacts, said sealing means defining with said mounting means and said housing a cavity within which at least a portion of the mating end of 

1. An underwater electrical connector and cable assembly comprising: a plug housing having a forward mating end, a rear conduit receiving end and a central axis from said forward end to said rear end; a first plurality of electrical contacts having mating ends and conductor receiving ends; means for mounting said first plurality of electrical contacts in said plug housing and in spaced relationship around said plug housing central axis so that the mating end of said contacts are at the mating end of said housing; sealing means for establishing a fluid-tight seal at The mating end of said plug housing, said sealing means including a forwardly biased portion that covers said contacts and maintains a fluid-tight seal when said contacts are covered and is rearwardly movable to expose said contacts, said sealing means defining with said plug housing a cavity within which at least a portion of the mating ends of said contacts mounted in said plug are disposed, said cavity communicating with the rear conduit receiving end of said plug housing; a first water-tight resiliently deformable, conduit connected at one end to the conduit receiving end of said plug housing, said conduit including therein a plurality of electrical conductors, each having one end connected to a respective conductor receiving end of said contact mounted in said plug; an electrically nonconducting fluid filling the remaining space in said conduit and said plug cavity whereby the mating ends of said contacts mounted in said plug are substantially surrounded by said nonconducting fluid, said forward mating end of said plug adapted to receive a receptacle having contacts within said plug housing so that said contacts mounted in said plug are in contact with the nonconducting fluid in said plug cavity upon mating of said plug with a receptacle; a receptacle housing having a forward mating end, a rear conduit receiving end and a central axis from said forward end to said rear end; a second plurality of electrical contacts having mating ends and conductor receiving ends; means for mounting said second plurality electrical contacts in said receptacle housing and in spaced relationship around said receptacle housing central axis so that the mating end of said contacts are at the mating end of said receptacle housing and said contacts mounted in said receptacle engage said contacts mounted in said plug upon mating of said plug and receptacle; sealing means for establishing a fluid-tight seal at the mating end of said receptacle housing, said sealing means including a forwardly biased portion that covers said contacts mounted in said receptacle and maintains a fluid-tight seal when said contacts mounted in said receptacle are covered and is rearwardly movable to expose said contacts mounted in said receptacle upon mating, said receptacle covering means defining with said receptacle housing a cavity within which at least a portion of the mating ends of said contacts mounted in said receptacle are disposed, said cavity communicating with the rear conduit receiving portion of said receptacle housing; the other end of said first water-tight, resiliently deformable conduit connected to the conduit receiving end of said receptacle housing, said nonconducting fluid filling said receptacle cavity also, whereby at least a portion of the mating ends of said contacts mounted in said receptacle are surrounded by said nonconducting fluid and whereby said nonconducting fluid in said conduit communicates with said plug cavity and said receptacle housing.
 2. An underwater disengageable electrical connector for interconnecting a plurality of electrical conductors, the electrical connector comprising: a receptacle element; a plug element disengageably insertable into said receptacle element, said plug element having a housing assembly carrying circumferentially spaced electrical contacts, a mating end, a conduit receiving end, and sealing means for establishing a fluid-tight seal at the mating end of said housing assembly, said sealing means including movable means for covering said contacts on said plug element and means for biasing said contact covering means in a contact covering position, said covering means biased to a contact covering position upon disengagement of said elements and a contact exposing position upon mating of the plug and receptacle; said receptacle element having a housing assembly carrying circumferentially spaced electrical contacts each engageable with a respective contact in said plug, a mating end, a conduit receiving end, and sealing means for establishing a fluid-tight seal at the mating end of said receptacle housing assembly, said sealing means including movable means for covering said contacts in said receptacle and means for biasing said receptacle contact covering means in a contact covering position, said receptacle contact covering means biased to a receptacle contact covering position upon disengagement of said elements and a contact exposing position upon mating of said plug and receptacle; said contacts in said plug and receptacle having a mating end and a conductor receiving end; a cavity within each of the plug and receptacle elements defined by said respective sealing means and said contact carrying housing assembly; a water-tight resiliently deformable conduit connected at one end to the conduit receiving end of said plug and connected at the other end to the conduit receiving end of said receptacle, said conduit including therein a plurality of electrical conductors connected to respective conductor receiving ends of said contacts in said plug and said contacts in said receptacle; and an electrically nonconducting fluid filling the remaining space in said conduit and said cavities in said housing assemblies.
 3. A disengageable electrical connector, as claimed in claim 2, in which said plug element includes a tubular housing having an open outer end and an inner surface, said inner surface mounting said plug contacts; said plug contact covering means comprising a hollow member telescoped inside said tubular housing; said plug biasing means comprising a first spring biasing said hollow member to a contact covering position; and at least one sealing ring mounted in said housing inner surface adjacent said housing open outer end and engageable with the external surface of said hollow member to form a seal therewith.
 4. A disengageable electrical connector as claimed in claim 2 in which said receptacle contact carrying part has an outer surface mounting said receptacle contacts; said receptacle contact covering means comprising a member telescoped over the receptacle contact carrying part and displaceable axially relative to said receptacle part; an annular seal mounted between said receptacle part and said member to form a seal therebetween; and said receptacle biasing means comprising a second spring biasing said member to a contact covering position.
 5. A disengageable electrical connector as claimed in claim 3 in which said receptacle contact carrying part has an outer surface mounting said receptacle contacts; said receptacle contact covering means comprising a member telescoped over the receptacle contact carrying part and displaceable axially relative to said receptacle part; an annular seal mounted between said receptacle part and said member to form a seal therebetween; and said receptacle biasing means comprising a second spring biasing said member to a contact covering position.
 6. An underwater electrical connector and cable assembly comprising: a housing having a forward mating end, a rear conduit receiving end, a rear conductor receiving portion, and a central axis from said forward end to said rear end; a plurality of electrical contacts having a mating end and a conductor receiving end; means for mounting said electrical contacts in spaced relationship around said housing central axis so that the mating end of said contacts are at the mating end of said housing; sealing means for establishing a fluid-tight seal at the mating end of said housing, said sealing means including a forwardly biased portion that covers said contacts and maintains a fluid-tight seal when said contacts are covered but is rearwardly movable to expose said contacts, said sealing means defining with said mounting means and said housing a cavity within which at least a portion of the mating end of said electrical contacts are disposed, said cavity communicating with the rear conductor receiving portion of said housing; a water-tight, resilienT deformable conduit connected to the conduit receiving end of said housing, said conduit including therein a plurality of electrical conductors connected to respective conductor receiving ends of said contacts; and an electrically nonconducting fluid filling the remaining space in said conduit and said housing cavity whereby the mating ends of said electrical contacts are substantially surrounded by said nonconducting fluid. 